Cindy - It's ok to have friends. It's ok to have male friends. It's even ok to bond with new friends. You have tons of shared experiences. But there's a difference between chatting in spurts every so often and constantly having messages back and forth. I think it's kind of a gray line, but as long as you're cognizant of it and know to check yourself, I think youll be ok.
As for your husband seeming happier...I wouldn't read too much into it. You're crushed inside, right? But what are YOU showing HIM? Hopefully a strong, happy woman moving forward with a life with or without him! So focus on you and your goals and let him do what he's going to do -- you can't control it anyway!!